Which is the best way to declare logger variable in java

Question

I just wantd to know which is the best way declare logger variable in java. Following are some declaration.

1> private static final Logger logger = Logger.getLogger(ServiceImpl.class);

2> private static Logger logger = Logger.getLogger(ServiceImpl.class);

3> private static final Logger LOGGER= Logger.getLogger(ServiceImpl.class);

4> private static Logger LOGGER= Logger.getLogger(ServiceImpl.class);

P.S I really appreciate if anybody knows another best alternative ways to declare looger variable.

Answer 1

All upper-case variable names are IMO out because you really aren't declaring/defining a constant but a static variable. Uppercase names are more suitable for "constants". That said, I'd personally go with the first approach.

private static final Logger logger = Logger.getLogger(ServiceImpl.class);

Answer 2

I vote for 3

 private static final Logger LOGGER = Logger.getLogger(ServiceImpl.class);

It's final since you don't change it and it's in uppercase since it's a constant.